Moving band icemaker with lubricant purification



Jan. 27, 1970 c. FIELD 3,

MOVING BAND ICEMAKER WITH LUBRICANT PURIFICATION Filed Dec. 15. 19674-Sheecs-Sheet 1 INVENTQR. CROSBY FIELD ATTORNEYS Jan. 27, 1970 I c.FIELD 3,491,543

MOVI NG BAND ICEMAKER WITH LUBRICANT PURIFICATION q Filed D80. 15, 19674 Sheets-Sheet 2 c R015 g YE EE L D m.& BY M, m r

ATTORNEYS c. FIELD Jan. 27, 1970 MOVING BAND IGEMAKER WITH LUBRICANTPURIFICATION 4 Sheets-Sheet 3 Filed Dec. 15, 1967 FIGJO FIG.

INVENTOR. CROSBY FIELD ATTORNEYS Jan. 27, 1970 c. FIELD 3,491,543

MOVING BAND ICEMAKER WITH LUBRICANT PURIFICATION Filed Dec. 15, 1967 4Sheets-Sheet 4 INVENTOR. CROSBY FIELD 4/ ATTORNEYS United States Patent3,491,543 MOVING BAND ICEMAKER WITH LUBRICANT PURIFICATION Crosby Field,8029 Harbor View Terrace, Brooklyn, N.Y. 11209 Filed Dec. 15, 1967, Ser.No. 691,055 Int. Cl. F25c /06, 7/12 US. C]. 62-72 8 Claims ABSTRACT OFTHE DISCLOSURE Congealing apparatus is disclosed which is particularlysuited for freezing ice and congealing liquid products. There are tworefrigerated plates over which a steel belt passes in two runs at anangle to the horizontal. A heat conducting lubricant is supplied beneaththe belt as it starts along each run. A special arrangement is providedfor removing the lubricant at the bottom of the path of the belt andspecial means is provided to evaporate water from the lubricant.

This invention relates to the art of congealing, and to apparatus foruse in connection therewith. Thus, for example, the invention may beused for making ice or in general for congealing material to convert itfrom a liquid state into a solid state. The present invention is relatedto those disclosed in my United States Letters Patents Nos. 2,610,479,2,610,476 issued Sept. 16, 1952, 2,990,199 issued June 27, 1961, and3,037,366 issued June 5, 1962.

An object of this invention is to provide improved freezing apparatus.Another object is to provide evaporators having a high rate of heattransfer and also with a surface hardened against erosion and protectedagainst corrosion. Another object is to provide very sensitive method ofmaintaining close and uniform contact between a stationary evaporatorand a freezing belt travelling over it. Another object is to provide amethod of tracking such belts. Still another object is to double theoutput of such a freezing belt by having it pass over the surface of anadditional evaporator on the return from the idler pulley to the drivepulley, after passing over the surface of the evaporator betweenthedrive pulley and the idler pulley, as disclosed in my previously citedpatents. Another object of the invention is to provide a separator, suchas an air dam, between the unfrozen liquid and the ice so as to producedr and subcooled ice on the belt. These and other objects will be inpart obvious and in part ointed out below.

In the drawings which show one embodiment of the invention:

FIGURE 1 is a right hand side view, with the side of the cabinetremoved;

FIGURE 2 is a diagrammatic view of the refrigeration system; I

FIGURE 3 is a rear view of the rear side of the cabinet removed; I

FIGURE 4 is a diagrammatic view of the system for tracking the belts; j

FIGURE 5 is a diagrammatic view of the belt lubricating system;

FIGURE 6 is a representation of the groove pattern Patented Jan. 27,1970 FIGURE 11 is a transverse sectional 'view of the belt; FIGURES 12and 13 are fragmentary side views of the portions of one evaporator;

. FIGURE 14 is a somewhat diagrammatic view showmg the manner in whichthe lubricant is collected; and,

FIGURES 15 to 18 are enlarged sectional views, respectively on lines 1515 and 1616 of FIGURE 12, 1717 on FIGURE 14, and 1818 on FIGURE 17.

Referring particularly to FIGURES 1 and 3 of the drawings, the ice makerhas four evaporators 1 assembled with evaporator frames 3 in the mannermore fully described hereinafter. The four sub-assemblies of evaporators1 and evaporator frames 3 are supported by a base frame 5 bolted to itmeans of brackets 7. Wooden skids 13 form an insulating foundation forthe metal base frame 5. This frame has two central support members 6 and8 which carry two centrally supported tubular arms 10 which, in turn,support slant portions of the frame 5 cantilevered on both sides. Thesetwo identical slant portions carry ice making sub-assemblies which arealso identical except that they are left-hand and righthandrespectively. The following description of the righthand subassembly(near side in FIGURE 1) applies equally to the one on the left. Theevaporator sub-assemblies are mounted in upper and lower slant positionsas shown. Pads of rubber 9 provide cushioned mountings on the brackets 7that permit final adjustment of the alignment of the evaporators 1 bymeans of bolts 11, which by means of their nut 12 control thecompression of the pads 9.

As best shown in FIGURE 1, a weldment 21 is bolted to the upper end offrame 5 and supports four parallel guide rods 23, two on each side. Theguide structure is completed by end plates 25 secured to the ends ofguide rods 23 by screws 27. Bearing block 31 is bored to slide on guiderods 23, thus permitting the hearings to move longitudinally of theslant frame. Each of the pair of bearing blocks 31 has a bearing 33 foran idler shaft 35. Mounted upon a free turning shaft is an idler pulley37. A drive pulley 19 is keyed to a shaft 17, which is rotatably mountedin the pair of bearings 15 secured to the lower ends of the slantmembers of frame 5. Freezing belt 39 is supported by pulleys 19 and 37and is tensioned between them as will be described more fullyhereinafter. Movement of belt 39 is imparted to it by drive pulley 19.Pulleys 19 and 37 are of rigid metal and have their cylindrical facescovered by a layer 41 of an elastomer, such as rubber (see FIGURE 14).Pulley 19 is driven as described hereinafter in connection with FIGURE7. The frame 5 is built so that the line between the centers of theshafts of the pulleys 19 and 37 may make with any horizontal line anyangle between 45 above to 45 below horizontal. As pulley 19 turns, itdrives the belt 39 so that it is drawn along the curved top surface ofthe upper evaporator and along the curved bottom surface of the lowerevaporator. The portions of the belt in contact with the evaporators aremaintained at a low temperature. As shown in FIGURE 4, the belt is heldunder tension by rods which bear upward against bearing blocks 31. Theforce on the inner rod 43 is produced by a coaxial spring 45 which isscrew adjusted for changing the pressure. The force on the outer rod 43is produced by a coaxial spring 45 which is screw adjusted for changingthe pressure. The force on the outer rod 43 is produced by a coaxialhydraulic cylinder 47 which is automaticaly controlled as describedhereinafter. The belt is driven by pulley 19 in a clockwise direction inFIGURE 1; that is, with the upper run moving to the right.

As shown in FIGURE 3 and FIGURE 11, each edge of belt 39 has bonded toit a continuous molded darn structure 49 of an elastomer, e.g. rubber.As shown in the cross vsectional view .of FIGURE. 11, this dam structurehas portions on both sides of the belt; the one portion to retain theliquid or fluid 40 (product) being congealed upon the congealing surfaceand the other portion to retain theliquid heat transfer lubricant 42which acts both as a lubricant and as a heat transfer agent between themetal of the belt and the evaporators. By maintaining a thin film ofheat transfer lubricant on the undersurface of the 'belt, anyirregularities in the surface in normal contact are compensated for.

The dams 49 are formed with a thinner section on the product side thanon the lubricant side. This prevents the edges where the dams 49 meetthe metal belt 39 at points 44 from getting cold enough for the product40 to freeze along its edges.

From drive pulley 19, shaft 17 is extended inwardly beyond bearing 15(see FIGURES 1 and 7) where sprocket 51 is keyed to it. Sprocket 51 isdriven from upper jack-shaft 53 by chain 55 and sprocket 56 which iskeyed to jack-shaft 53. Jack-shaft 53 is turned by sprocket 57, drivenby chain 63 from motor 291, gearmotor sprocket 59 and gear-motor shaft61. Jack-shaft 53 turns'in two bearings 65, bolted one on either side tothe center post of frame 5. A lower jack-shaft 67 turns in two bearings69 which are similarly bolted to the center post of frame 5. J ack-shaft67 is turned by sprocket 71 from chain 63. A hydraulic pump sprocket 73is driven from this jack-shaft by a chain 79 and a sprocket 75, and 73and chain 79. The sprocket 81 of the lubricant pump is also driven bychain 63. Vertical adjustment of sprocket 81 produces the proper tensionin the chain 63. Proper tension in chain 55 is maintained by verticaladjustment of bracket 87 which supports an idler sprocket 83 and itspivot 85.

The evaporator (see FIGURE 8) in contact with the freezing belt is aplate 95 of a high heat conducting material, i.e., aluminum, to one sideof which has been attached, by brazing or welding, parallel refrigeranttubes 97. The other side of the plate 95 is coated with a hard erosionresistant yet high heat transfer material, i.e., molybdenum, into thepores of which has been inserted a corrosion resistant coat, i.e., apolyvinylchloride, rendered high heat conducting by the inclusiontherein of graphite. At the respective ends, tubes 97 are welded intoheaders 99 and 99a (see also FIGURE 1), the flanges 101 (FIGURE 8) ofwhich are connected to the refrigerant piping described hereinbelow. Inthis embodiment, there are ten refrigerant tubes 97, and the tubes areslightly flattened to increase the contact with the plate, thusincreasing the heat transfer rate between the plate 95 and therefrigerant in the tubes. Additional heat transfer is provided byenclosing the tubes in a layer of heat conducting cement 103 'which isalso in contact with the plate 95.

As shown in FIGURE 6, lubricant groovesv are pro.- vided on the otherside of the plate 95. Evaporator plate 95 is supported (FIGURE 8) bythree radius guide plates 105, of an insulating material, which in turnare supported on their lower edges by the three transverse angles 107which, together with two longitudinal angles 109 form the evaporatorframe 3. Radius guide plates 105 are maintained in the correcttransverse positions by rods 111 and spacer nuts 113 which also securethe outer guide plates to the longitudinal angles 109 of the frame. Thesub-assembly includes two insulating strips 115 which. extend along thecurved sides of the respective outer radius guide plates 105 and upalongside the edge of the evaporator plate. Near the lower edge of strip115 an insulated heater wire 117 is secured. It is covered by a metalfoil strip 119 and then by a plastic insulating strip121. The heatproduced by the electric current in Wire 117 is thus conducted by thefoil 119 up to the edge of the evaporator isolated by insulators on bothsides.

The. heat along this .lineprevents frost accumulation under the edge ofthe metal freezing belt 39.

The upper and lower evaporator assemblies are identical except only inthe handling of the heat transfer lubricant. FIGURE 12 illustrates thelubricant feed end of the upper evaporator and FIGURE 13 illustrates theother end, and FIGURE 6 shows the top of the evaporator. The directionof belt travel is indicated by arrows 123. Referring to FIGURE 12,casting 125 and insulating block 127 provide end support for plateallowing clearance for header 99 and (see also FIGURE 6) lubricant feedblock 129, being firmly bolted to the frame at transverse angle 107. Themethod of securing plates 95 to end castings 125 is shown in FIGURE 15which is a cross section near the end of the evaporator. Screws 120 incountersunk holes in insulating block 127 secure the evaporator to endcasting 125, screws 122 in countersunk holes in plate 95 secure it toblock 127. Thus there is no metallic contact for heat conductivitybetween plate 95 and end casting 125. Insulating block 127 preventsfrosting on casting by conductivity from plate 95.

As shown in FIGURE 16, lubricant is fed into feed block 129 by a nipple131 and thence by means of holes 124 in screws 126 through the plate 95to the belt as more fully described hereinbelow. Any excess lubricantnot carried up by the belt is collected in drain groove 133 (FIGURE 12).Referring to FIGURE 13, casting 125a and insulating block 127a providesupport for the other end of plate 95. A transverse windshield wiper 135wipes the bottom surface of the belt as it moves away from theevaporator surface, and removes the film of lubricant and it collects indrain 137. Referring to FIG- URE 8, a metal sleeve 139, larger indiameter than header 99 covers this header concentrically between theadjacent radius guide plate 105 and the flange 101. Heater wire 117makes approximately three turns around sleeve 139. Heat conductingcement is used to increase the effectiveness of wire 117 in heatingsleeve 139.

After all these evaporator parts have been assembled, the space belowthe plate 95 and tubes 97 is filled with a chemically expandedinsulation (such as a polyurethane foam) flush with the bottom of radiusguide plates 105. This insulation also fills the space between headers99, 99a and sleeves 139 after insulating between the headers the lowerevaporator assembly is the same as that of the upper evaporatorassembly, except that end has a lubricant feed block 129 and connectionnipple 131. There are no lubricant drain connections in casting 125b orisulating block 127b and no wiper 135, since the lubricant drains intothe inside of the lower part of the and the end castings 125 and 125a.The construction of belt. Its return to the system will be describedhereinbelow in connection with FIGURE 5. Both upper and lower evaporatorplates 95 have lubricant grooves 141 as shown in FIGURE 6.

REFRIGERATION OF EVAPORATOR FIGURE 2 is a diagrammatic representation ofthe refrigeration system for the evaporators 1 which omits accessoriessuch as controls, oil separator and others Well known in the art. Onthe'low pressure side two levels of operation are used since theevaporators are operated flooded. The upper evaporator 1a operates inparallel off surge drum 145a and the lower evaporators 1b operate inparallel off surge drum 145b. Liquid refrigerant from condenser 147 isfed through conduit 149 into the surge drums through their respectivevalves 151a and 151b which are controlled by level responsive elements153a and 153b so that the levels in the surge drums are maintained attheir respective levels 155a and 155b which are the respective optimumoperating levels. The refrigerant liquid flows by gravity from the surgedrums into the evaporators. The surge drums are constructed as disclosed in my Patent No. 3,037,366. The refrigerant vapor formed in theupper evaporator flows through conduits 157a into surge drum 145a,displaced by liquid refrigerant under the static head at level 155a. Theliquid refrigerant flows through an orifice in a nozzle into each of theevaporator tubes 97 to provide proper distribution of refrigerantbetween the tubes and increase velocity and turbulence therein resultingin a higher rate of heat transfer as disclosed in my Patent No.3,037,366. The refrigerant vapor reurns to the compressor 171 via hesurge drum 145a where any liquid carried with it is separated out beforeit enters suction line 163. Oil return is obtained by bleed-off tubes165a and 167a from the lower evaporator headers through the oil stills169a and 16911 and back into the suction line 163 to compressor 171. Oilstill 169a is heated by a small amount of discharge gas from compressordischarge line 173 through tubes 175 and 177a to the top of surge drum145a. The lower evaporators 1b and surge drum 1451; operate together, inthe same way as the upper evaporator 1a and surge drum 145a, but theoperation is based on the lower liquid level 155b.

LUBRICANT SYSTEM FIGURE 5 is a diagrammatic representation of the systemwhich maintains a thin film of heat transfer lubricant between theevaporators and the belts. This lubricant may be an antifreeze compoundsuch as an aqueous solution of propylene glycol. The two evaporators andtheir respective associated elements on the right hand side of thisembodiment have been omitted for clarity. A supply of lubricant ismaintained in reservoir 179. When the belts are driven, pump 181supplies lubricant to the leading ends of evaporators, through filter182, 1a and 1b via capillaries 183 and 1831b and feed blocks 120 (seealso FIGURE 12). Each of the capillaries 183 may be of a differentlength to ensure equal and proper distribution of lubricant between thefour evaporators. Pump 181 is driven by sprocket 81 as previouslydescribed With reference to FIGURE 7. Used lubricant from wiper 135(FIGURE 13) and drain 137 returns to reservoir 179 via drain line 185.Drain line 187 returns the lubricant from drain groove 133 (FIGURE 12)to reservoir 179. Referring to FIGURE 5, the lubricant used by the lowerevaporator 1b collects on the inside of the belt 39 at its low pointwhere drive pulley 19 is located.

The molded dam structure 49 at each edge of the belt retains thislubricant (see FIGURES 17 and 18) so that it flows in along the edges ofthe inside of the pulley. Each of these edges has a large numberofequally spaced grooves 188 which lead to four aligned arcuate grooves189 adjacent the web 190 of the pulley (see FIGURE 14). Grooves 188 arespiral so that the rotation of the pulley causes them to direct thelubricant from the extreme edge of the pulley into grooves 189.Positioned at the trailing end of each groove 189 is a cup 191 which isopen on their leading sides to its groove. Hence, as the pulley movesclockwise from the bottom position in FIGURE 14, the lubricant flowsfrom the groove 189 into its cup. The cup is otherwise closed except fora discharge tube 192 which at this time extends upwardly, but which hasits discharge end extending out beyond the edge of the belt toward astationary drain tray 193. Upon continued movement of the pulley the cupis tipped toward its upright position and the lubricant starts todischarge through tube 192 into the drain tray which is positioned atthe side of the pulley adjacent the pulley shaft. Hence, as each cupmoves past the lowest point in its travel, it scoops up a quantity oflubricant and then deposits it into tray 193 from which it returnsthrough a tube 195 to reservoir 179. The arrangement is such that thelubricant is completely discharged from each cup before its tube movesover the pulley shaft and no lubricant is deposited on the shaft. Whenthe ice maker is stopped a timer keeps the belts39 running for a presetperiod with the refrigeration off. During this period solenoid valve 197opens diverting all lubricant from the discharge of pump 181 toreservoir 179 while the above described lubricant system returns thelubricant in use to reservoir 179 also to prevent loss of lubricant byoverflow on shutdown.

Since the lubricant used is water soluble, it may be gradually dilutedby moisture condensed from the air as the ice maker operates. Further,since the freezing point is raised by dilution, this accumulation ofwater must be constantly removed to avoid possible freeze-up. Since theboiling point of the lubricant and water mixture is a function of itswater content a rectifier 199 is used, maintained at a practicallyconstant temperature by means of an electric immersion heater andthermal switch. The temperature of the rectifier is set to correspond toth boiling point of the desired concentration of lubricant solution. Asmall convection flow in tubes 201 maintains the solution concentrationin reservoir 179 substantially the same as that in rectifier 199 withoutheating the solution in the reservoir. Thus when the solution is dilutedin the reservoir 179, it is also diluted in rectifier 199 depressing itsboiling point below the rectifier temperature. The boiling in thereservoir drives water out of the solution, thus concentrating it untilits boiling point reaches the predetermined rectifier temperature, awhich time the boiling stops. AA reflux condenser 203 having glass ballpacking is used over the rectifier to minimize loss of lubricant carriedoff by the escaping steam.

HYDRAULIC TRACKING SYSTEM FIGURE 4 is a diagrammatic representation ofthe hydraulic tracking system which automatically keeps belt 39 centeredon evaporators 1a and 1b and drive pulley 19 and idler pulley 37 as itruns. A reservoir 205 holds a supply of hydraulic fluid. Pump 207(driven by sprocket 73 in FIGURE 7) draws fluid from reservoir 205 tobuild up pressure in pressure line 209, limited by a pressure regulator211 Which bleeds into a drain line 213 to return spent fluid toreservoir 205. Each of the two belts in this embodiment is tracked byusing this pressure in the following manner: a control valve 215 isoperated by a roller arm 217 which follows the molded edge 49 of belt39. When belt 39 starts to the left of center it causes arm 217 to turncontrol valve 215 so as to permit more fluid into cylinder 47 increasingthe tension slightly in the left side of the belt 39 which moves thebelt back to the center position. When belt 39 starts to the right ofcenter it causes arm 217 to turn control valve 215 so as to vent fluidfrom cylinder 47 decreasing the tension slightly in the left side of thebelt 39 which moves the belt back to the center position. Spring 45maintains a practically constant preset tension on the right side of thebelt. The changes in tension on the left side of the belt required fortracking are referenced to this tension and are so slight that they haveno noticeable effect on the belt. A check valve 221 is provided betweenthe control valve 215 and the cylinder 47. This valve remains open aslong as there is pressure in line 209. When the pump stops and itspressure falls, check valve 221 closes to hold cylinder 47 in the properposition for restarting without excessive tracking movement.

THE WATER SYSTEM Identical systems apply the water (or other liquid orfluid) to be solidified to the refrigerated portions of each of the twobelts 39. One of these, therefore, will be described with reference to:FIGURES 1 and 3. The liquid enters through tube 223 controlled by floatvalve 225 which maintains a level 227 in sump 229. It is circulated bypump 231 from the sump through tube 233 to T 235. To supply the upperfreezing portion of the belt, the liquid rises from T 235 through tube237 to the high end of upper precooler trough 239, down this trough andthen down a second precooler trough 241 on to the belt 39. It

is distributed across the belt by a corrugated weir 243 at the end oftrough 241. Cooling coils 244 and 246 are brazed to the underside oftroughs 239 and 241, respectively. The excess liquid that is not froozenas it flows downward and to the left, over the upper refrigeratedportion of belt 39 returns to the sump after flowing over drive pulley19. It is prevented from enterng ice chute 245 by an air curtain from arow of nozzles 247 in a. header 249. To supply the lower portion of thebelt the liquid passes through tube 251 to four sprinkler nozzles 253connected to tube 251 by TS 255. Nozzles 253 are so located that theyproduce complete coverage of the lower freezing portion of belt 39. Thenozzles 253 and tube 251 are secured into a run-down pan 257 which hassides curved to fit the belt. vRubber edges 259 on these sides form asplash seal against the rubber edges of belt 39. Another rubber strip261 across the belt at the top of the upper end of run-down pan 257forms a splash seal at this point. An air curtain from a row of nozzles263 in header 265 prevents any unfrozen liquid from following down thebelt into ice chute 245. Hence it is all deflected into run-down pan 257and returns to sump 229 at point 267. A finned cooling coil 269 issubmerged in the liquid in sump 229 for precooling the returned unfrozenliquid and the make-up from the float valve 225. A blower 271,direct-driven by motor 273 provides the air for the air curtains. Itsdischarge is divided into four tubes 275. The two shown supply headers247 and 265. The two behind them supply the air curtains for the otherbelt. A splash pan 2'62 fits snugly on top of sump 229. It has an icechute 245 built into it and also has a support trough for air header 249and run down trough for the excess unfrozen liquid from the upperfreezing surface. A lower extension 245A of the ice chute is built intosump 229 to guide the ice harvested from the lower cooling surfacethrough the bottom of the ice maker out of contact with the unfrozenliquid.

PREC-OC-LER REFRIGERATION As has been indicated above, the liquid to befrozen is precooled by cooling coils on upper troughs 239 and 241 andfinned lower coils 269 immersed in the lower sumps 29. These coils arecooled by the evapoartion of a refrigcrant in a system in conformitywith general practice diagrammed in FIGURE 10. The liquid refrigerantflows from the receiver 277 under control of solenoid valve 279. Itsflow is properly distributed between the four evaporators by means offour adjustable needle valves 281. The bulb 283 of thermal switch 285 issecured at one of the upper precooler troughs 241 so that it is incontact with the liquid as it fiows onto the belt. The switch 285controls solenoid valve 279. Thus the amount of cooling is regulated bythe temperature of the precooled liquid to be frozen.

GENERAL ARRANGEMENT As may be seen in FIGURES 1 and 3, the cold portionsof the ice maker are enclosed in a cabinet 287 which is comprised ofreadily removable insulated panels joined at their edges by angle strips289. Thus the front, rear, and sides of this cabinet may each be removedin one piece for ready service access. Since the slant portions of frame5 are cantilevered, replacement of belt 39 is simple after removal ofthe side and rear cabinet sections, the run-down pan 257, and thesplash-pan 262. Disconnecting rods 43 permits bearing blocks 31 to slidedownward and to the left along with idler pulley 37 producing clearancefor removal of belt 39. A thin section of the cabinet projects at thelower front center so that gear motor 291 may be mounted outside theinsulated space. Its output shaft 61 projects through the panel withdrive sprocket '59 on the inside. Thus the motor heat is excluded.

What is claimed is:

1. In congealing apparatus a combination of an endless metal belt havingan outer surface upon which ice may be formed and having dam means atits edges which protrude from the opposite side to form continuous rims,mounting means for said belt which support said belt with two runs whichextend between end portions, drive means to drive said belt at one ofsaid end portions, a pair refrigerated plates presenting groovedsurfaces respectively along said runs between said rims with said beltmoving along said surfaces when it is driven, one of said end portionsof said belt being at higher elevation than the other whereby one ofsaid runs is an upper run along which said belt moves upwardly and theother run is a lower run along which said belt moves downwardly,

means to supply heat conducting lubricant between said belt and saidsurfaces, and means to collect and remove said lubricant from betweensaid rims at the lower end of said lower run, said means to collect andremove lubricant comprising cup means which is mounted to move with saidbelt from the lower end of said lower run and to receive and raise thelubricant and means to discharge the lubricant from said cup means.

2. Apparatus as described in claim 1 which includes means to rectify thelubricant after it has been removed.

3. Apparatus as described in claim 1 wherein said belt is work-hardenedMonel metal.

4. In congealing apparatus a combination of an endless metal belt havingan outer surface upon which ice may be formed and having dam means atits edges which protrude from the opposite side to form continuous rims,mounting means for said belt which support said belt with two runs whichextend between end portions, drive means to drive said belt at one ofsaid end portions, a pair of refrigerated plates presenting groovedsurfaces respectively along said runs between said rims with said beltmoving along said surfaces when it is driven, each of said refrigeratedplates having a surface in contact with said belt Which is formed ofsprayed molybdenum having pores in which heat conducting plastic hasbeen placed, one of said end portions of said belt being at a higherelevation than the other whereby one of said runs is an upper run alongwhich said belt moves upwardly and the other run is a lower run alongwhich said belt moves downwardly, means to supply heat conductinglubricant between said belt and said surfaces, and means to collect andremove said lubricant from between said rims at the lower end of saidlower run.

5. Apparatus as described in claim 4 wherein each of said refrigeratedplates has grooves along said surfaces, means for supplying the heatconducting lubricant to the bottom side of said belt as it starts alongeach of said runs, and wherein said apparatus includes a drumconstituting the mounting means between the bottom ends of said runs,groove means in said drum within which the lubricant collects, andwherein said means to remove the lubricant comprises cup means mountedwithin said drum and positioned to dip lubricant from said groove meansand to lift the lubricant upwardly, and means to receive the lubricantfrom said cup means at an elevated level.

=3. Apparatus as described in claim 5 wherein said means to receive thelubricant comprises tube means mounted upon said cup means and extendingradially inwardly, stationary means to receive the lubricant from saidtube means, and means to return the lubricant to a lubricant supplymeans.

7. In congealing apparatus a combination of an endless metal belt havingan outer surface upon which ice may be formed and having dam means atitsedges which protrude from the opposite side to form continuous rims,mounting means for said belt Which support said belt with two runs whichextend between end portions, drive means to drive said belt at one ofsaid end portions, a pair of refrigerated plates presenting groovedsurfaces respectively along said runs between said rims with said beltmoving along said surfaces when it is driven, one of said end portion ofsaid belt being at a higher elevation than the other whereby one of saidruns is an upper run along which said belt moves upwardly and the otherrun is a lower run along which said belt moves downwardly, means tosupply heat conducting lubricant between said belt and said surfaces,pulley means providing the mounting means for one end of said belt,adjustable spring means providing tension at one side of said pulleymeans, hydraulic means providing tension at the other side of saidpulley means, and control means to control said hydraulic means andthereby guide said belt.

8. In congealing apparatus the combination of means providing a movingsurface upon which a product is congealed, and means to impel a streamof air against the surface of the congealed product Within apredetermined zone of the movement of said surface thereby to limit thezone of uncongealed liquid, said moving surface being that ReferencesCited UNITED STATES PATENTS 1,046,307 12/1912 Kind 62345 X 2,990,1996/1961 Field 6272 3,037,366 6/1962 Field 62345 3,356,182 12/1967Robinson et a1. 1846 WILLIAM E. WAYNER, Primary Examiner US. Cl. X.R.

